SylvieJane is my absolute favourite. It doesn't need Sylvia - it's wonderful on its own and that's how I prefer it. FlorenceWren is also amazing. The other two aren't bad, but these are the two I'd definately go with.

I love all of the combos, with the exception of OliveHelen. I like both of those names, but the flow is off. My favorites are SylvieJane and VivianAlice. Alice is a bit too similar to Elsa for a first name, but I think it's fine as a middle.